Narrative:

I am writing to advise NASA and the FAA of 2 problems encountered on an IFR letdown/approach to sat in VFR conditions. I have specific suggestions at the end of the narrative. The 2 problems were: 1) I was issued a routing with conflicting altitude instructions by austin approach. 2) subsequent loss of communications with austin approach prevented clarification of the altitude instructions. We were approaching sat from the nnw with a progressive letdown to 8000 ft north of centex VOR (identify cwk) and was handed off to austin approach on 118.8 MHZ. Austin approach later issued the following clearance: 'proceed to centex VOR, then cleared to sat via marcs 7 arrival, after centex proceed direct marcs intersection, maintain 6000 ft.' the descent to 6000 ft MSL was completed, and as we approached marcs intersection I called austin approach to clarify what altitude they wanted us at: 6000 ft or the 3100 ft shown on the marcs 7 arrival after marcs intersection. The confusion arose since we were given an instrument arrival procedure (marcs 7) but the controller already changed the routing (centex VOR to marcs intersection) from the published route of centex VOR to stasy intersection to marcs intersection, and it appeared the altitude also which is why I attempted to obtain clarification. There was no answer to any of my radio calls. I even changed radios, switched mikes -- no difference. There were brief periods of silence, however, there were so many aircraft on the frequency we did not hear austin approach. At one point another aircraft called approach and said 'don't you hear (my aircraft number) calling you?' I've lost radio communications/no contact or relay from approach control so my altitude now should be 6000 ft (which is the highest altitude for the segment being flown per 91.185(C)(2)) which is where I remained. We were traveling at 190-195 KTS so after 10 mins of calling approach, listening, changing radios and mikes, we reached the clearance limits of criss intersection. I then made a VFR right turn north (away from san antonio international) and began a VFR descent to land elsewhere as soon as practicable per 91.185(B). I tuned the same radios to san antonio tower 119.8 MHZ and immediately heard the tower calling me. I responded and said that I had been calling approach for the past 15 mins and no answer. I was then handed off to sat approach, issued a 230 degree heading and climb to 4000 ft (we were already passing through 3000 ft) and vectored to an uneventful landing at sat. Here are my suggestions to prevent this problem: 1) austin approach needs some kind of alarm system to let the controller know when his radio is malfunctioning and/or they need an additional approach frequency and controller because there were too many aircraft on the frequency at the same time hindering/preventing communications. 2) if austin approach is going to issue an instrument arrival procedure then do so without modification, or issue a clearance/instruction on what you want and don't mention the arrival procedure! In this case, a modification to the route and altitude was issued which was further aggravated by a loss of communications which could have created a dangerous situation in a busy terminal area.

Google
 

Original NASA ASRS Text

Title: THE LOSS OF COM FREQ CREATES CONFUSION AS TO WHAT PROCS TO FOLLOW FOR A C421 ATP PLT ON THE MARCS 7 ARR NE OF SAT, TX.

Narrative: I AM WRITING TO ADVISE NASA AND THE FAA OF 2 PROBS ENCOUNTERED ON AN IFR LETDOWN/APCH TO SAT IN VFR CONDITIONS. I HAVE SPECIFIC SUGGESTIONS AT THE END OF THE NARRATIVE. THE 2 PROBS WERE: 1) I WAS ISSUED A ROUTING WITH CONFLICTING ALT INSTRUCTIONS BY AUSTIN APCH. 2) SUBSEQUENT LOSS OF COMS WITH AUSTIN APCH PREVENTED CLARIFICATION OF THE ALT INSTRUCTIONS. WE WERE APCHING SAT FROM THE NNW WITH A PROGRESSIVE LETDOWN TO 8000 FT N OF CENTEX VOR (IDENT CWK) AND WAS HANDED OFF TO AUSTIN APCH ON 118.8 MHZ. AUSTIN APCH LATER ISSUED THE FOLLOWING CLRNC: 'PROCEED TO CENTEX VOR, THEN CLRED TO SAT VIA MARCS 7 ARR, AFTER CENTEX PROCEED DIRECT MARCS INTXN, MAINTAIN 6000 FT.' THE DSCNT TO 6000 FT MSL WAS COMPLETED, AND AS WE APCHED MARCS INTXN I CALLED AUSTIN APCH TO CLARIFY WHAT ALT THEY WANTED US AT: 6000 FT OR THE 3100 FT SHOWN ON THE MARCS 7 ARR AFTER MARCS INTXN. THE CONFUSION AROSE SINCE WE WERE GIVEN AN INST ARR PROC (MARCS 7) BUT THE CTLR ALREADY CHANGED THE ROUTING (CENTEX VOR TO MARCS INTXN) FROM THE PUBLISHED RTE OF CENTEX VOR TO STASY INTXN TO MARCS INTXN, AND IT APPEARED THE ALT ALSO WHICH IS WHY I ATTEMPTED TO OBTAIN CLARIFICATION. THERE WAS NO ANSWER TO ANY OF MY RADIO CALLS. I EVEN CHANGED RADIOS, SWITCHED MIKES -- NO DIFFERENCE. THERE WERE BRIEF PERIODS OF SILENCE, HOWEVER, THERE WERE SO MANY ACFT ON THE FREQ WE DID NOT HEAR AUSTIN APCH. AT ONE POINT ANOTHER ACFT CALLED APCH AND SAID 'DON'T YOU HEAR (MY ACFT NUMBER) CALLING YOU?' I'VE LOST RADIO COMS/NO CONTACT OR RELAY FROM APCH CTL SO MY ALT NOW SHOULD BE 6000 FT (WHICH IS THE HIGHEST ALT FOR THE SEGMENT BEING FLOWN PER 91.185(C)(2)) WHICH IS WHERE I REMAINED. WE WERE TRAVELING AT 190-195 KTS SO AFTER 10 MINS OF CALLING APCH, LISTENING, CHANGING RADIOS AND MIKES, WE REACHED THE CLRNC LIMITS OF CRISS INTXN. I THEN MADE A VFR R TURN N (AWAY FROM SAN ANTONIO INTL) AND BEGAN A VFR DSCNT TO LAND ELSEWHERE AS SOON AS PRACTICABLE PER 91.185(B). I TUNED THE SAME RADIOS TO SAN ANTONIO TWR 119.8 MHZ AND IMMEDIATELY HEARD THE TWR CALLING ME. I RESPONDED AND SAID THAT I HAD BEEN CALLING APCH FOR THE PAST 15 MINS AND NO ANSWER. I WAS THEN HANDED OFF TO SAT APCH, ISSUED A 230 DEG HDG AND CLB TO 4000 FT (WE WERE ALREADY PASSING THROUGH 3000 FT) AND VECTORED TO AN UNEVENTFUL LNDG AT SAT. HERE ARE MY SUGGESTIONS TO PREVENT THIS PROB: 1) AUSTIN APCH NEEDS SOME KIND OF ALARM SYS TO LET THE CTLR KNOW WHEN HIS RADIO IS MALFUNCTIONING AND/OR THEY NEED AN ADDITIONAL APCH FREQ AND CTLR BECAUSE THERE WERE TOO MANY ACFT ON THE FREQ AT THE SAME TIME HINDERING/PREVENTING COMS. 2) IF AUSTIN APCH IS GOING TO ISSUE AN INST ARR PROC THEN DO SO WITHOUT MODIFICATION, OR ISSUE A CLRNC/INSTRUCTION ON WHAT YOU WANT AND DON'T MENTION THE ARR PROC! IN THIS CASE, A MODIFICATION TO THE RTE AND ALT WAS ISSUED WHICH WAS FURTHER AGGRAVATED BY A LOSS OF COMS WHICH COULD HAVE CREATED A DANGEROUS SIT IN A BUSY TERMINAL AREA.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.